Method and apparatus for testing tubing



Sept. 22, 1953 W. M. BUSH ETAL 1 EITHOD AND APPARATUS FOR TESTING TUBING 2 Sheets-Sheet 1 Filed April 26, 1948 FIG: 6.

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Patented Sept. 22, 1953 UNITED STATES PATENT OFFICE METHOD AND APPARATUS FOR TESTING TUBING Application April 26, 1948, Serial No. 23,346

8 Claims.

This invention relates to a method and apparatus for testing tubing such as is used in oil wells.

In running a string of tubing into a well it is highly desirable to test each stand of tubing as it is assembled with the string that is being lowered into the well to determine whether or not the stand is in a leaky condition or whether it has been so weakened that its use in the well may prove dangerous. By testing each stand of tubing as it is assembled with the string, faulty tubing stands may be detected and removed from the string and either repaired or discarded.

An object of the present invention is to provide an improved method and apparatus by which each stand may be subjected to a predetermined measurable hydraulic pressure and Which is so designed that the testing apparatus may be easily and conveniently shifted from stand to stand as it is assembled with the string in performing the successive tests.

Another object of the invention is to provide a method and apparatus for testing stands of tubing having the above mentioned characteristics which will involve a loss of very little, if any, hydraulic fluid between the upper and lower barriers that are established within the tubing. Consequently in shifting and testing apparatus from stand to stand very little time or water is used to fill the space between the barriers with water or like liquid used to perform the test. In this manner the testing of the stands of tubing can be easily and quickly performed without involving any substantial loss of time in running the tubing into the well.

With the foregoing and other objects in view, which will be made manifest in the following detailed description and specifically pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein:

Figure 1 is a schematic view of the upper portion of a well having a string of tubing therein and illustrating schematically the application thereto of apparatus embodying the present invention;

Fig. 2 is a. view on a somewhat enlarged scale of portions of the apparatus illustrated in Fig. l;

Fig. 3 is a similar view but illustrating the manner in which the apparatus is shifted from stand to stand;

Fig. 4 is a partial view in side elevation illustrating details of construction associated with the lower barrier;

Fig. 5 illustrates a portion of the apparatus shown in Fig. 4 in another position thereof; and

Fig. 6 is a vertical section through the coupling device through which hydraulic pressure may be supplied in the course of effecting a test.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, T indicates generally a string of tubing that is being lowered into an oil well and which is made up of stands of tubing. Each stand, in turn, may be composed of one or more sections of pipe indicated at I 0, l l and I2 which are connected together such as by collars 13. In the construction illustrated each stand is made up of three pipe sections although the exact number in a given stand is variable. The testing apparatus embodying the present invention consists essentially of a length of sucker rod M or other relatively inextensible rod. At the top and bottom of this rod there are barriers which are spaced from each other a distance approximately equal to the length of the stand made up of the pipe sections I0, H and I2. The lower barrier may be provided by a pair of swab rubbers indicated at I 5 and I6 which may be mounted on a threaded stem l1 secured to the bottom of the sucker rod. This threaded stem carries below the lower swab rubber a slip cone I8 around which there are slips I9 having downwardly facing wickers 20. These slips are urged into their contracted or collapsed position by means of a surrounding tension coil spring 2| but may be forced upwardly with relation to the slip cone by means of pins 22 which extend through an enlargement 23 formed on the stem l1 below the slip cone. The pins 22 are carried by an upper collar 24 to which bowed friction springs 25 are connected. The lower ends of these friction springs are connected to a lower collar 26, the downward movement of which is adjusted by means of a nut 21 that is screwed onto the stem ll. The bowed friction springs 25 are bowed sufliciently so as to be engageable with the interior of the tubing T so that whenever the sucker rod l4 and the stern I1 are lowered relative to the friction springs the pins 22 will engage the slips I 9 and force them upwardly on the slip cone l8 causing the slips to expand into engagement with the interior of the tubing. Conversely, whenever the sucker rod H and the stem I! are lifted relatively to the friction springs 25 the pins 22 will descend allowing the slips I9 to descend with relation to the slip cone l8 and to contract. As a means of controlling the relative movement between the sucker rod and the stem I1 and the friction springs 25, a sleeve 28 is rigidly secured to or formed integral with the upper collar 24. This sleeve has a downwardly bifurcated slot 29 formed therein into which a pin or boss 39 on the stem II extends. The longer side of this slot, indicated at 3!, is vertically arranged while the smaller side of the slot, indicated at 32, is circumferentially spaced therefrom but communicates at its upper end with the top of the Side 3|. By thi arrangement. on turning the sucker rod I4 and stem I1 so as to position the pin 30 at the bottom of the small side 32 of the slot 29 it is possible to lower the device within the tubing without causing the friction springs to efiect a setting of the slips !9. Thus in the position shown in Fig. 4, the apparatus may be lowered into the tubing to the desired distance without effecting a setting of the slips. However, when the apparatus has been thus lowered and the sucker rod is subsequently lifted, the pin 30 on the stem I'I will pass upwardly out of the shorter side 32 of the slot and be cammed by its inclined top over to the top of the longer side 3I of the slot. Consequently, if the sucker rod is then lowered, the pin 30 may descend through the longer side SI of the slot which is sufficiently long to enable descent of the slips I9 into engagement with the pins 22 and thus secure a setting of the slips,

At the top of the sucker rod I4 there is secured a tube or conduit 33 on which the upper barrier formed by a swab rubber 34 is mounted. Below the upper swab rubber a lateral outlet 35 is formed in the conduit 33. Above the upper swab rubber one or more lateral inlets 35 are provided a short distance above a shoulder 36. The top of the conduit 33 has a valve seat 31 for a vent valve 38. This valve, however, normally drops by gravity from the valve seat 31 against a restriction in the conduit indicated at 39. Above the valve seat the conduit has one or more venting outlets indicated at and M and has a head indicated at 42 presenting a downwardly facing shoulder 43 that may be engaged by any suitable grabbing device such as that indicated at 43 (see Fig. 3). As a means for supplying fluid pressure to the conduit to be discharged between the barriers at the top and bottom of the sucker rod, a coupling device is provided consisting of a sleeve 44. This sleeve is applicable over the head and top of the conduit until it is positioned against the shoulder 36. On its interior there may be 0 rings 45 or equivalent packing for forming leakproof seals above and below the inlet apertures 35'. A conduit generally indicated at 46 leads to the sleeve 44 intermediate its ends and has a valve seat 48 therein for a ball valve 49. This ball valve when seated extends inwardly in the sleeve 44 a sufficient distance so as to be engageable by the sides of the top of the conduit 33. Consequently, when the sleeve is in applied position, as shown in Fig. 6, the ball valve 49 is unseated from its seat 48 by the conduit 33, thu opening conduit 46 to conduit 33. Fluid may then flow from conduit 46 through the clearance 50 to the inlet apertures 35', pass downwardly through the conduit 33 and be discharged into the tubing through the outlet 35 between the upper and lower barriers formed by the swab rubbers.

The conduit 46 receives its fluid such as water from a water supply or reservoir 5| which is connected through a check valve 52 to a small cylinder 53. The outlet from this small cylinder passes through check valves 54 and 55 through conduit 46 to the sleeve 44. Incorporated in the conduit 46 there is a pressure gauge 56 and a manually operable relief Valve 51 which can be opened at the completion of a test. In the small cylinder 53 there is a small piston 58 which is rigidly connected to a large piston 59 that is reciprocable in a cylinder 69. This cylinder receives water under pressure from a pump such as a centrifugal pump GI and by means of conventional valves (not shown) piston 59 can be reciprocated. This produces reciprocation of the small piston 58 and due to the differential in size between the pistons 58 and 59 the water expelled from the small cylinder 53 will be expelled at relatively high pressure measurable by means of the pressure gauge 56.

In testing the tubing as the various stands are assembled the testing apparatus is first lowered into the tubing with the slips I9 in their contracted positions and with the pin 30 in the position shown in Fig. 4. Consequently, during the initial lowering of the construction into the tubing the slips I9 will not be set although the friction springs 25 may be frictionally rubbing on the interior of the tubing. When the apparatus has been lowered into a position so that the lower barrier formed by the lower swab rubbers i below the joint at the bottom of the stand made up of pipe sections III, II and I2 the sucker rod I4 and its attached conduit 33 may be elevated a short distance. This causes the pin 30 to rise within the side 32 and to be cammed over to the top of the longer side 3I as previously explained. On subsequently lowering the sucker rod I4 the friction springs 25 which tend to frictionally remain stationary in the tubing will efiect a setting of the slips I9 by means of the pins 22. The sleeve 44 can then be applied over the top of the conduit 33 and the pump actuated to supply water under high pressure through conduit 46 to the space within the tubing between the upper and lower barriers provided by the swab rubbers. The pressure gauge 56 is then watched to determine whether or not a drop in pressure ensues. If the pressure drops this indicates that a leak is present somewhere in the stand made up of pipe sections III, II and I2.

If it is determined from the pressure gauge 56 that the stand of pipe tested does not leak, the sleeve 44 is lifted from the top of the conduit 33 and a new or subsequent stand of pipe is attached to the top of pipe section I2 and the entire tubing is lowered into the well so that the subsequent stand then occupies the position of pipe sections III, II and I2. During this lowering of the tubing in the well the barriers, together with the sucker rod I4 will, of course, be lowered along with the illustrated stand composed of pipe sections III, II and I2 so that when the subsequent stand has been lowered into the well the testing device will be disposed within that stand which is subjacent the topmost stand. The grab or similar device illustrated at 43' is then lowered into the tubing and caused to engage the head 42 and the entire structure is pulled upwardly within the tubing to assume the position shown in Fig. 1. During this upward movement the sucker rod I4 and the stem I 'I are elevated with relation to the friction springs 25 so that the friction springs, together with their collars 24 and 26, descend. allowing the slips I9 to contract. During the upward movement also that water which is within the tubing between the barriers is not lost or wasted but is carried upwardly within the tubing by the lower swab rubbers. When the apparatus has been lifted into the added stand the sucker rod M can again be lowered relatively to the friction springs 25 to again effect a setting of the slips I 9. The sleeve 44 may then be reapplied to the conduit 33 and measurable fluid pressure supplied to the interior of the tubing between the barriers to effect a testing of the added stand.

If the added stand should prove leaky or should have burst under the testing pressure, the sleeve 44 is removed and the sucker rod I4 is elevated to unset the slips l9. While in its elevated position the sucker rod is then given a partial rotation so as to position the pin or boss 30 in the shorter side 32 of the slot 29. In this position the testing apparatus can be lowered in the tubing without setting the slips and the device is lowered into the subjacent stand in the tubing. When it reaches this position the sucker rod is again elevated and lowered returning the pin 30 to the long side 3| of the slot and to effect a setting of the slips [9. The tubing can then be raised and the added stand which has proven leaky can be removed and either repaired or discarded. A substitute stand can then be attached to the tubing, the grab 43 lowered to connect onto the testing device and it can be raised into the substituted stand and the test made thereof in the manner previously described.

In the shifting of the testin apparatus, either up or down, it will be observed that the Water in the tubing between the barriers moves with the apparatus and that there is very little loss thereof other than by that occasioned in wetting the interior of the tubing. This slight amount of loss may involve the entry of some air. Consequently, whenever air is present between the barriers or within the conduit 33, the liquid that is introduced from the pump causes the air to rise through conduit 33 and to escape past the vent valve 38. The valve 38 may either be a float valve or a valve which will be carried upwardly by the liquid to cause it to seat on its seat 3'! whenever the conduit 33 is completely filled with liquid. The arrangement of the valve 49 is such that whenever it is removed from the conduit 33 it automatically closes, preventing escape or loss of liquid from the pump through the flexible conduit 46.

As illustrated on the drawing, in performin a test on a given stand it is advisable to position the lower barrier formed by the lower swab rubbers l5 and I6 below the joint or connection between the stand and the string of tubin that is within the well. In this manner a given test will include the joint and the major portion of the length of the stand and with the repetition of the tests on added stands the balance or uppermost portion of a given stand will be included in the test across the joint of the added stand.

It will be appreciated from the above described method and apparatus that tubing may be easily and quickly tested in the course of its introduction into the well. Furthermore, only a relatively small amount of water or similar liquid is consumed or lost in the course of making the test. The shifting of the apparatus from one stand to another can be easily and quickly performed and when the apparatus is allowed to remain in any set position it is adequately supported against descent within the tubing by means of the set slips. Control of whether these slips are to be set or not is always available by manipulation at the surface.

Various changes may be made in the details of construction without departing from the spirit and scope of the invention as defined by the appended claims.

We claim:

1. The method of testing tubing as it is being made up and lowered into a well which consists of establishing spaced connected barriers within the tubing adjacent the top thereof, supporting one of the barriers within the tubing, applying measurable pressure to the space between the barriers and observing whether the pressure decreases due to leakage and if the tubing tested does not leak attaching an additional stand of tubing to the string in the well, lowering the string and attached stand while the barriers remain supported in the string, drawing the barriers upwardly into a position to test the attached stand and repeating the test.

2. A tubing tester comprising means providing spaced barriers adapted to seal off a joint of a tubing, a rod connecting the barriers, slip means attached to one of the barriers by which it may be self-supported within the tubing, there being a passage through the rod and the upper barrier and opening into the space between the barriers, and means for supplying measurable fluid pressure to said passage.

3. A tubing tester comprising means providing spaced barriers adapted to seal off a joint of a tubing, a rod connecting the barriers, slip means attached to one of the barriers by which it may be self-supported within the tubing, there being a passage through the rod and the upper barrier and opening into the space between the barriers, means for supplying measurable fluid pressure to said passage, and a detachable head connected to the upper end of the rod and adapted to be grabbed to elevate the device Within the tubing.

4. A tubing tester comprising a rod, barrierproviding means adjacent the top and bottom of the rod adapted to form spaced barriers within the tubing in which the tester is positioned, settable slips attached to the lower barrier, means by which the slips may be optionally caused to set within a tubing Or to be lowered therethrough without setting, means providing a conduit through the upper barrier and opening into the space between the barriers, a head on the conduit above the upper barrier by which the tester may be engaged and lifted within a tubing, and coupling means applicable to the conduit by which measurable hydraulic pressure may be supplied to the conduit.

5. A tubing tester comprising a rod, barrierproviding means adjacent the top and bottom of the rod adapted to form spaced barriers within the tubing in which the tester is positioned, settable slips attached to the lower barrier, means by which the slips may be optionally caused to set within a tubing or to be lowered therethrough without setting, means providing a conduit through the upper barrier and opening into the space between the barriers, a head on the conduit above the upper barrier by which the tester may be engaged and lifted within a tubin';, coupling means applicable to the conduit by Which measurable hydraulic pressure may be supplied to the conduit, and vent means adjacent the top of the conduit for venting air but not liquid therefrom.

6. The method of testing a sequence of lengths of tubing that are connected end to end by joints as they are lowered in a well which consists of lowering at least one length of tubing in the well, with said lowered tubing having two longitudinally spaced fluid holding barriers slidably movable within the interior thereof, applying measurable fluid pressure to the confined space in the interior of said tubing between said barriers and observing whether the pressure decreases due to leakage of said fluid from the interior to the exterior of said tubing connecting a second length of tubing to the upper end of said tested length of tubing by a joint and lowering said joined tubing in said well, raising said barriers to positions where the lowermost thereof is in the upper portion of said tested length of tubing but below said joint, applying measurable fluid pressure to said confined space to test said joint and second length of tubing, and continuing to alternately add lengths of tubing to said tested tubing in said well and lowering and testing said added lengths until the desired amount of tubing is disposed in said well.

7. The method of testing a sequence of lengths of tubing that are connected end to end by joints as they are lowered in a well which consists of lowering at least one length of tubing in the well, with said lowered tubing having a fluid holding barrier disposed in the lower portion thereof, applying measurable fluid pressure to the interior of said lowered tubing above said barrier and observing whether the pressure decreases due to leakage of said fluid from the interior to the exterior of said tubing, connecting a second length of tubing to the upper end of said tested length of tubing by a joint and lowering said joined tubing in said well, raising said barrier to the upper portion of said tested length of pipe but below said-joint, applying measurable fiuid pressure to said second length of tubing and said joint and observing whether the pressure decreases due to leakage of said fluid, continuing to alternately add lengths of tubing to said tested tubing in said well and lowering and testing said 8 added lengths until the desired amount of tubing is disposed in said well.

8. The method of testing a plurality of lengths of tubing and the joints connecting same as they are moved vertically in a well which consists of positioning space-confining means therein and thus establishing a longitudinally movable confined space within the interior of said tubing that is of such length as to at least extend through the length of said tubing and the joint on one end thereof, applying measurable pressure to said confined space and observing whether the pressure decreases due to leakage that may occur through the particular tubing and joint interval being tested, moving said space-confining means and plurality of lengths of tubing and joint vertically in unison in a series of steps, moving said space-confining means substantially the same distance as that moved in unison with the tubing but in the opposite direction after each of said steps, and applying measurable pressure to said confined space after each of said steps.

W. M. BUSH. CHAS. H. COLLE'I'I.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,221,733 Henderson Apr. 3, 1917 1,652,472 Erwin et a1 Dec. 13, 1927 1,812,945 Granger July 7, 1931 2,067,499 Millmine Jan. 12, 1937 2,085,972 Halliburton July 6, 1937 2,109,745 Hayward Mar. 1, 1938 2,164,195 Walthermire June 27, 1939 2,216,268 Fritsohe Oct. 1, 1940 2,280,785 Boynton Apr. 28, 1942 2,481,013 Henderson Sept. 6, 1949 2,545,102 Miller Mar. 13, 1951 

